Breakdown of Мы долго смотрели на хищника, охотящегося на зайца.
мы
we
на
on, at / by (transport) / to (a place) / to (in answer to)
смотреть
to watch / to look at / make sure (in a warning)
долго
for a long time
Questions & Answers about Мы долго смотрели на хищника, охотящегося на зайца.
How would this sentence look if we used a который clause instead of the participle охотящегося?
You would say Мы долго смотрели на хищника, который охотится на зайца. The active present participle охотящегося directly replaces the relative pronoun and verb который охотится to make the sentence more compact, which is a common stylistic choice in written Russian.
Why does the participle охотящегося have the ending -егося here?
Participles agree with the noun they modify in gender, number, and case. It modifies хищника, which is masculine and in the accusative case because of the preposition на. Since хищник is an animate noun, its accusative form looks exactly like the genitive. The participle matches this, taking the masculine animate accusative ending -его before adding the reflexive particle -ся.
Since the participle ending -его ends in a vowel, shouldn't the reflexive particle be -сь instead of -ся?
That rule applies to standard verb conjugations, where -ся becomes -сь after vowels (like он охотился vs она охотилась). However, participles are a strict exception to this rule. In Russian, participles always keep the full -ся ending, even after a vowel.
Why do we see the preposition на twice in this sentence?